#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <deque>
#include <set>

#define flr(x, l, r) for (int x = l; x <= r; ++x)
#define frl(x, r, l) for (int x = r; x >= l; --x)
#define fmp(x, t) for (int x = h[t]; ~x; x = ne[x])
#define LL long long
#define mt memset
#define my memcpy
#define szf sizeof
#define INF 0x3f3f3f3f
#define in(x) scanf("%d", &x)
#define out(x) printf("%d", x)
#define inll(x) scanf("%lld", &x)
#define outll(x) printf("%lld", x)
#define pn printf("\n")
#define con continue
#define bk break
#define vc vector
#define pb push_back
#define sz size
#define PII pair<int, int>
#define x first
#define y second
#define P_q priority_queue
#define ft front
#define pf push_front
#define popf pop_front
#define it insert
#define ct count

using namespace std;

const int N = 110;

int n;
int g[N][N], dist[N];
bool st[N];

int prim() {
    mt(dist, 0x3f, szf dist);
    dist[1] = 0;
    
    int res = 0;
    flr (i, 1, n) {
        int t = -1;
        
        flr (j, 1, n)
            if (!st[j] && (t == -1 ||  dist[t] > dist[j])) 
                t = j;
                
        if (i && !st[t]) res += dist[t];
        st[t] = true;
        
        flr (j, 1, n) dist[j] = min(dist[j], g[t][j]);
    }
    
    return res;
}

int main() {
	in(n);
    
    mt(g, 0x3f, szf g);
    flr (i, 1, n)
        flr (j, 1, n)
            in(g[i][j]);
    
    out(prim()), pn;
    
    return 0;
}